He coined the phrase Industrial Tourism.
He has a great collection of essays, called Desert Solitaire ISBN 0345326490 (alternate, search), and his most famous book, The Monkey Wrench Gang ISBN 0060956445 (alternate, search) (fiction).
While Abbey himself promoted the ideas of monkeywrenching (environmental terrorism to some), he did not have any special fondness for any group, especially not the SierraClub?.